For decades, there has been an increasing trend towards automatization in the fruit and horticultural sectors. Labor-intensive tasks such as fruit recollection and processing have steadily incorporated innovative solutions that reduce the need of manual work. However, there are still some tasks for which current solutions lack enough efficiency and throughput to replace a more traditional approach. For example, automatization becomes particularly challenging when small items need to be handled individually, and when operations need to be applied to a particular area of the fruit item with a certain degree of precision.
This is the case of decapping processes of strawberries (and other fruits and horticultural fruit items with a similar structure), whose calices need to be removed before consumption or incorporation into processed goods such as drinks, jams, yogurts, etc. In order to remove each calyx in an automated system, each piece of previously-retrieved fruit needs to be individually oriented, aligning the calyx with the decapping element (typically some sort of blade in a fixed position). If this alignment is not performed accurately enough, either parts of the calyx may be left within the fruit, affecting its final flavour; or part of the edible main body may be removed, resulting in an unnecessary waste of food. Furthermore, each fruit must be held tightly enough as to maintain its position during retrieval and decapping, but not as tight as to fruit damage in the sensitive fruit skin. Finally, the task of maintaining health regulations and requirements in an automated decapping system is also challenging, both due to accidental contact with un-hygienized surfaces, and to degradation caused by the acid nature of the fluids that are released during the process.
For example, British patent GB 2,377,161 B presents a system for strawberry calyx removal where fruit items are kept in place during decapping by means of pneumatic suction, in order to prevent damaging the fruits. However, this system does not solve the critical task of aligning the fruits, requiring either manual labor or an external automated sorting and orienting system.
In order to perform the aforementioned orientation, some systems rely on automated vision. For example, PCT publication WO 2014/144268 A1 and US 2013/064950 A1 disclose computer-controlled strawberry pre-processing systems based on calyx detection through vision systems. However, after orientation detection, limited control on the fruit positioning is provided, reducing overall accuracy and efficiency.
Furthermore, all known techniques present limitations in their tolerance to shape variations, that is, when the same kind of good presents different shapes, it may result in errors in the visual recognition algorithms and subsequent decapping.
Chinese patent CN 102,686,119 A discloses an alternative approach which automatizes both fruit orientation and decapping. Each piece of fruit is provided through conveying means which hold the strawberry by the stem, hence keeping fruits in an approximately vertical orientation. A pair of rotating circular blades on both sides of the conveying means' path are applied to the upper part of the strawberry main body, severing the inedible part. However, this approach presents some limitations. On one hand, as the stem length may vary from fruit to fruit, the height at which the calyx is cut may also very, resulting in either leaving residual calyx or removing too much edible fruit. On the other hand, the system relies on sharp blades to perform the decapping, resulting in the release of acidic fluids which need to be periodically cleaned from the blades, reducing overall system efficiency.
Therefore, there is still a need for an automated fruit processing apparatus for fruits and horticultural goods, capable of efficiently and accurately removing calices,